Method of drawing butt-weld pipe.



Pia-715,856. Patented Dec. 16. I902.

P. PATTERSON.

METHOD OF DRAWING BUTT WELD PIPE.

, (Application filer! m 14, 1901. nnewea Jan. 2, 1902. (lo Modal.)

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UNITED STATES PATENT OFFICE.

PETER PATTERSON, OF MCKEESPORT, PENNSYLVANIA, ASSIGNOR TO NATIONAL TUBE COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

METHOD OF DRAWING BUTT-WELD PIPE.

SPECIFICATION forming part of Letters Patent No. 715,8 56, dated December 16, 1902.

Application filed May 14, 1901. Renewed January 2, 1902. Serial Nn- 88,066. (No Specimens.)

To all whom it may concern:

Be it known that I, PETER PATTERSON, a resident of McKeesport, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Methods of Drawing Butt-Weld Pipe; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to the manufacture of butt-weld tubing. It is especially applicable to the manufacture of butt-weld tubing from flat strips or plates, and I will describe it in connection therewith; but it is to be understood that it is not limited thereto, but may be practiced with any suitable tube-blanks, such as U-shaped or like tubular blanks.

In the practice which has heretofore prevailed the blanks, in the form of flat plates, are generally charged into the furnace at a speed somewhat greater than the speed at which they are withdrawn. It is the object of the present invention to provide for increasing the speed of withdrawal, so that the speed of withdrawal may closely approximate the charging speed. One of the difficulties in the way of greatly increasing the speed of withdrawal is the danger that the jaws of the tongs may lose their hold on the plate when they are first subjected to the jerk incident to the engagement of the hook with the drawchain or of the reciprocating drawing apparatus with the power mechanism. \Vhen such engagement takes place, the tongs are compelled to overcome the static inertia of the plate lying in the furnace, and the wider or longer the plate the greater'is the amount of inertia to be overcome. Another stage of danger in the operation is when the forward end of the plate first encounters the weldingbell. The shock of impact at that time, if the speed of drawing is too great, may result in the disengagement of the tongs from the plate. Another difficulty in the way of greatly increasing the speed of withdrawal where a continuously-running draw-chain is employed has arisen from the fact that the connection of the pulling-hook with the continuouslyrunning draw-chain has to be effected manuallythat is to say, it is the business of the attendant, commonly called the buggyboy, to connect the pulling-hook with the reins of the tongs and to then insert the prongs of the pulling-hook into a link of the moving chain. In view of these difiiculties the practically permissible speed of the withdrawal has been limited to a maximum of about-four hundred (400) feet per minute when buttwelding smaller-sized pipe and of about three hundred (300) feet per minute when buttweldinglarger-sized pipe. To overcome these difficulties, and thereby permit the time of withdrawal to be diminished and more perfectly balance the time of feeding, the invention consists, generally stated, in heating a tube-blank in a suitable furnace and when its edges are raised to a welding heat drawing the same at a relatively slow speed out of the furnace until after the front end thereof has entered the welding-bell and then increasing the drawing speed and so drawing the remainder of the pipe at a relatively higher speed through the bell.

One of the special advantages of the invention is that it permits the continuous buttwelding at a single operation of much longer blankssuch, for example, as blanks longv enough to make when transversely severed two or more pipes of standard length, as described and claimed in my application filed October 5,1900,SerialNo.32,l32,andin so doing by bringing the speed of withdrawal closer to the speed of charging to obtain more perfect heat conditions. This provides for diminution of the scrap, as the transverse severing of the same into pipes of standard lengths affords two finished ends not requiring to be trimmed, and,further, there is a large increase of output, because the operations for feeding and withdrawing such double-length pipe are practically the same as for the single-length pipe, and the double-length pipe can be drawn in very little more time than that now occupied in drawing a single-length pipe.

To enable others skilled in the art to practice my invention, I will describe the same more fully, referring to the accompanying drawings, in which- Figure 1 is a side elevation, and Fig. 2 is a plan View, of apparatus adapted to carry out the same.

In the practice of the invention I employ any suitable welding furnace of suitable length, according to the length of tubing to be formed, employing therefor with doublelength pipe a furnace practically double the length of the ordinary furnace when in use, the furnace 1 being in the neighborhood of forty feet in length and having a hearth 2, which is of suificient width to receive six or more plates or other blanks to be welded into tubing. The furnace is preferably of the regenerative type, heated by gas, either manufactured or natural. It has the chargingopening 3 at the rear end and the drawingopening4 at the forward end, and it may either be charged by hand or by any suitable mechanical means. In front of the furnace is located any suitable drawing apparatus, that illustrated in the present case being the drawbench 5, which is adapted to move in front of the furnace, so as to be brought into line with any one of the plates or blanks lying on the hearth thereof, the draw-bench illustrated being pivoted, as at 6, and mounted on suitable standards or rollers 7, so as to swing into line with the blanks in the furnace. Where such a draw-bench is employed, it is preferably provided with a continuously-running draw-chain, and as my invention can be as well illustrated in connection with such contin uously-running chain as with a reciprocating drawing mechanism I will describe that form of apparatus as illustrating means suitable for carrying out the invention. Such draw-bench has at its forward end the bellholder 8 for receiving the welding-bell 9, as is common in the art, and with a continuously-running draw-chain 10, which passes over a sprocket-wheel 11 at the forward end of the bench and a sprocket-wheel12 upon the drive-shaft 13. Thedriving-shaftisadapted to be driven at a variable speed, so as to impart variable speeds to the draw-chain, and

this can be accomplished in any suitable way,

that illustrated in the drawings being by means of two electric motors, both geared to the driving-shaft 13. One motor 14 has its armature-shaft l5 geared to the driving-shaft 13 by suitable gears, such as the wheels 13", while in line with said armature-shaft is the armature-shaft 16 of another motor 17, which is adapted to be coupled with the armatureshaft 15 by means of a friction-clutch-such, for example, as the electric clutch 18 illustrated, which is adapted to be energized by a current coming from any suitable source of power through the conductors 19 to said clutch, said circuit being controlled by the switch 20, the blade of which is connected to the reciprocating rod 21, which is suitably mounted on standards and hangers 22 on the side of the draw-bench and in position to be readily grasped by the buggy-boy in order to open and close said switch. By means of the motors illustrated or other suitable mechanism the driving-shaft 13 is designed to be normally driven by the motor 14 at the relatively slow speed as will prevent undue shock in overcoming the static inertia of the plate in the furnace and on the first contact of the same with the welding bell and will permit the insertion by the buggy-boy of the hook in the draw-chain, while the other motor and its armature -shaft 16 are designed to be driven at a much higher speed, so as when coupled to the shaft 15 by the clutch 18 to increase the speed of the drawchain and provide for an increase in speed of the blank in passing through the welding-bell after it has entered the same. Where motors are employed, as illustrated in the drawings, the motor 14 may be arranged to be driven, for example, at one hundred and seventy-five revolutions per minute, the gearing connections imparting from the same a speed of about three hundred feet per minute to the draw-chaimwhile the motor 17 may be designed to run at about three hundred revolutions per minute, so that when connected up with the driving-shaft it will impart a speed of about five hundred feet per minute to the draw-chain. Both motors are arranged to run continuously; but ordinarily the electric clutch 18 is not energized, so that the draw-chain will be driven by the motor 14 at the lower speed above referred to. When it is desired to operate the chain at the higher speed through the electric or like clutch, connection is made from the more rapidly running motor 17 to the draw-chain, so imparting the increased speed to the same, the armature-shaft of the slower-running motor traveling idly when the clutch connection is made at the higher speed and the high-speed motor imparting the necessary speed and power for the drawing of the pipe. In accomplishing this result where electrical motors are employed, as shown, in order to prevent the slow-speed motor from acting as a generator it is differentially wound, so as to offer no resistance to the driving of the chain by the high-speed motor.

In practicing the invention with apparatus such as that above described the plates or blanks 23 are charged into the furnace in any suitable way, the invention being applicable to the welding of U-shaped or like blanks as well as to the welding of flat plates, though it is especially advantageous in the welding of flat plates because of the greater friction within the welding-bell caused by the turning up of the flat plate into tubular form.

In the preferred method of practicing the invention and where it is employed in the making of double-length pipe the plates or other blanks are fed to the furnace by any suitable charging mechanism or by hand, the speed of charging being greater than the normal speed of the draw-chain and generally being nearly double the normal speed of such chain. As soon as one of the plates is at the proper heat for drawing, which the welder can determine by examination of the forward end of the plate, he connects the drawingtongs or other pulling device to the plate and passes the welding-bell over the same, and where the continuously-running draw-chain is the pulling power employed, as illustrated in the apparatus shown, the buggy-boy by means of his hook connects the tongs to the draw-chain while that chain is traveling at its normal or slower speed. As soon as the front end of the blank is in this way drawn into the welding-bell and the welding operation commences the buggyboy or other operator by means of any suitable operating mechanism, such as the reciprocating rod 21, connects up the high-speed motor with the driving-shaft, such as through the electric clutch 18, causing the draw-chain to travel at the higher speed, approximately twice that of its normal speed, and as the increase of speed is only the difference between the two speeds of the draw-chain there is little shock in passing from one to the other and there is little or no liability of the pulling of the tongs or other drawing-tool from the heated pipe, though a high speed is attained in the drawing of the pipe. The static inertia of the blank lying on the hearth is thus overcome bya pulling force at comparatively slow speed, and the plate travels at this speed until its forward end strikes the welding-bell, which on account of the slow speed will be without serious shock, whilethe increased speed can be imparted to the plate gradually through the action of the friction-clutch and without serious jar. The

electric clutch or like friction-clutch neces-' sarily acts in a yielding manner and so provides for passing from the lower to the higher speed gradually and progressively and without shock or jar. Furthermore, the electric motor acts yieldiugly, so that there is no sudden shock in overcoming the static inertia of the tube-blank in the furnace nor when the end of said blank strikes the bell nor in changing from the slower to the higher speed. In so providing for drawing the pipe at high speed I am enabled to considerably increase the output of the furnace because of the quicker travel of the heated blank from the furnace and throughthe Welding-bell, so making it possible to more quickly introduce another blank into its place for heating, the fresh blank being, if desired, charged before the heated blank has been entirely withdrawn from the furnace. I am also able to make the time of charging and the time of withdrawing practically balance each other, and so give almost the ideal conditions for heating the plates. On account of the increased speed of drawing in making double-length pipe I overcome in great measure the liability of the stretching or sagging of the pipe during the drawing operation. In this way I overcome serious difficulties in the welding of double-length pipe, and so aid in increasing the output and reducing the relative labor and cost. While accomplishing these desirable ends, I avoid the liability of the forming of cobbles and overcome the mechanical difficulty of making connection between the tongs and draw-bench experienced in using a high-speed draw-chain.

While my invention has peculiar advantages in the manufacture of tubing from flat plates where the same are charged into the rear of the furnace and withdrawn from the front thereof, the invention may be employed with tubular or like skelp, and where the blanks are withdrawn from the same end into which they are charged the invention has certain advantages in connection with such processes.

The apparatus shown and described in this application is not claimed herein, but is claimed in my application filed May 14, 1901, Serial No. 60,139.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The herein-described method of forming butt-weld tubing, which consists in introducing a tube-blank into a heating-furnace, raising its edges to a welding heat, drawing the same out of the furnace until its front end has entered a welding-bell and then increasing the speed of drawing of the blank through the bell.

2. The herein-described method of forming butt-weld tubing, which consists in introducing a tube-blank into the rear end of the furnace-chamber at a relatively high speed of charging, raising its edges to a welding heat, and then drawing the heated blank ataslower speed out of the furnace until the front end has entered a welding-bell and then increasing the speed of drawing of the blank through the bell.

3. The herein-described method of forming butt-weld tubing, which consists in introducing a flat plate into the rear end of the furnace-chamber at a relatively high speed, raising its edges to a welding heat, and then drawing the heated plate at a relatively slower speed out of the furnace until the front end has entered a welding-bell and then increasing the speed of drawing of the plate through the bell.

- t. The herein-described method of forming butt-weld tubing, which consists in introducing a tube-blank into a heating-furnace, raising its edges to a welding heat and drawing the same out of the furnace until its front end has entered a welding-bell and then gradually and yieldingly increasing the speed of drawing, and drawing the remainder of the plate through the bell at a higher speed.

5. The herein-described method of forming butt-weld tubing, which consists in introducing into a furnace-chamber a flat plate of sufficient length to form two or more tubes of standard length, raising its edges to a welding heat and drawing the same out of the furnace until its front end has entered a welding-bell, and then drawing the remainder of the plate through the bell at a higher speed.

6. The herein-described method of forming butt-Weld tubing, which consists in introducing a tube-blank into a heating-furnace, raising its edges to a welding heat, drawing the same out of the furnace with a yielding, or elastic pull, until its front end has entered a Welding-bell, and then gradually and yieldingly increasing the speed of drawing, and drawing the remainder of the blank through the bell at a higher speed.

7. The herein-described method of forming butt-Weld tubing, which consists in introducing a tube-blank into a heating-furnace, raising its edges toa welding heat, and then drawin; the same by means of an electric motor out of the furnace until its front end has entered a welding-bell, and then increasing the speed of drawing of the blank through the bell.

In testimony whereof I, the said PETER PAT- TERSON, have hereunto set my hand.

PETER PATTERSON. Witnesses JAMES I. KAY, ROBERT C. TOTTEN. 

